Antitumor effect of free rhodium (II) citrate and rhodium (II) citrate-loaded maghemite nanoparticles on mice bearing breast cancer: a systemic toxicity assay.

Breast cancer is one of the most prevalent cancer types among women. The use of magnetic fluids for specific delivery of drugs represents an attractive platform for chemotherapy. In our previous studies, it was demonstrated that maghemite nanoparticles coated with rhodium (II) citrate (Magh-Rh2Cit) induced in vitro cytotoxicity and in vivo antitumor activity, followed by intratumoral administration in breast carcinoma cells. In this study, our aim was to follow intravenous treatment to evaluate the systemic antitumor activity and toxicity induced by these formulations in Balb/c mice bearing orthotopic 4T1 breast carcinoma. Female Balb/c mice were evaluated with regard to toxicity of intravenous treatments through analyses of hemogram, serum levels of alanine aminotransferase, iron, and creatinine and liver, kidney, and lung histology. The antitumor activity of rhodium (II) citrate (Rh2Cit), Magh-Rh2Cit, and maghemite nanoparticles coated with citrate (Magh-Cit), used as control, was evaluated by tumor volume reduction, histology, and morphometric analysis. Magh-Rh2Cit and Magh-Cit promoted a significant decrease in tumor area, and no experimental groups presented hematotoxic effects or increased levels of serum ALT and creatinine. This observation was corroborated by the histopathological examination of the liver and kidney of mice. Furthermore, the presence of nanoparticles was verified in lung tissue with no morphological changes, supporting the idea that our nanoformulations did not induce toxicity effects. No studies about the systemic action of rhodium (II) citrate-loaded maghemite nanoparticles have been carried out, making this report a suitable starting point for exploring the therapeutic potential of these compounds in treating breast cancer.

Dextran-functionalized magnetic fluid mediating magnetohyperthermia combined with preventive antioxidant pequi-oil supplementation: potential use against cancer.

This work aimed to test a dextran-functionalized magnetic fluid (DexMF) sample in mediating magnetohyperthermia to treat an advanced clinical Ehrlich-solid-tumor, to verify the effects of oral antioxidant administration of pequi-oil on this treatment and to investigate the potential of these treatments for future use as an adjuvant in cancer therapy. Animals received the treatments: (a) filtered water (control); (b) tumor implantation and no treatment (tumor group); (c) tumor implantation followed by intratumoral injection of DexMF and alternating current magnetic field exposure (MHT group) for three consecutive days; (d) oral pequi-oil supplementation followed by tumor implantation and the same treatment as group MHT (PMHT group). Analyses took place 1 and 2 weeks after tumor implantation. Both treatments were effective in increasing the tumor necrosis process and controlling tumor growth, besides keeping lymphocyte-dependent immunity. Although the MHT treatment was more efficient after the first week in reducing DNA damage to blood peripheral leucocytes, PMHT therapy appeared to be more effective with the advance of the carcinogenesis process after the second week. Our findings evidence the potential use of DexMF mediating magnetohyperthermia in cancer treatment and also suggest that the preventive pequi oil administration could increase the efficiency of this process.